This proposal is directed towards the development of new methodology for the stereoselective construction of complex polycyclic ring systems and the application of this methodology to the synthesis of structures of biological significance. We describe herein the extension of the intramolecular vinylogous amide photocycloaddition/retro-Mannich/Mannich sequence that we have developed for the synthesis of perhydroindoles to the synthesis of bridged tricyclic aminoketones via intramolecular photocycloaddition of vinylogous imides. The development of the asymmetric variant of the photocycloaddition reaction will be examined, in the context of syntheses of three different naturally occurring compounds containing the azabicyclo[ 3.2.1]octane moiety: 1) peduncularine 1, from the genus Aristotelia, which displays activity against human breast cancer cells, 2) securinine 2, which is a specific GABA receptor antagonist, and 3) sarain A 3, a marine alkaloid with antitumor, antibacterial, and insecticidal activity produced by the sponge Reniera sarai.